Multistage high-pressure centrifugal pump



March 24, 193. E. VOGEL MULTSTAGE HIGH PRESSURE CENTRIFUG'AJ PUMP atented Mar. 24, 19311 ERNST VOGEL, F STOCKERAU, NEAR VIENNA, AUSTRIA MULTISTAGE HIGH-PRESSRE CENTRIFUGAL' PUMP Application flied February 8, 1927, Serial No.

Multi stage high pressure centrifugal pumps, especially boiler feed pumps for highpressure boilers, up to the present are built in such a manner, that the shaft carrying the y 3 rotor-wheels is supported on both sides of the pump, thus requiring on the one side a lowpressure or suction-stung-.box and on the other a high-pressure-stufIing-box.

According to the present 'invention the high-pressure-stufiing-box is eliminated, be-

' cause it is very diiicult to keep it constantly tight at the hivh rotary speed of the shaft in the warm, or ,Ilot water, and, therefore, retightening very frequently becomes neces- 16 sary. i

This, according to the invention, is obtained by providing bearings for the pumpshaft at the suction-side of the pump only, hence making the other end of the shaft selfsupporting, and by neutralizing, wholly or partly, the axial pressure (high-pressure) on the free cross-section-area of the non-supported shaft-end by means of a tighteningdevice, which permits, at all or at only some or at only a single one of the rotor-wheels, the

hydraulic pressure active at their periphery to act on the wheel-face facing the suctionside as an axial-pressure opposite in direction -to the axial-pressure mentioned above.

In the exam le shown in the drawing as a longitudinal view partly in section, a pump is driven by an electric motor or a steam-tur- Therefore a strong shaft 1 is used which is supported, at the suction-side of the pump, at the suction-canal 2, in two bearings, f. i. ballbearindgs 3 and 4. These bearings are arranigte so far from each other that the pumpsha Iis self-'supporting without danger of bending or vibration. The shaft carries a number of rotor-wheels 5 which cooperate with the corresponding fixed casings 6.

' These casin 6 are surrounded b outer casings? to w ich the casing-like llds 8 and 9 are connected for supportin the ump. The

lid 8 carries the suction-stun -dbx 11 accessible throu h opening 10 and, y means of a suitably a joined hollow lengtheningiece 12, the bearings 3 and mentioned a ove.

60 The lid 9 forms the high-pressure chamber 13 166,768, and in Austria February 9, 1926.

to which, at .14, the pressure-conduit "is" joined. In this chamber the free end of the shaft l protrudes and the total cross-area of this end is acted upon by the hydraulic highl that the hydraulic pressure, active at the circumference of the wheels and transmitted to both side-faces of the Wheels, meets a larger annular pressure-area (ring-breadth 17) at the side-face of the wheels facing the suctionside of the pump than kat the side-face (ringbreadth 18) facing the pressure-side of the pump, so that the diiierence of the Vtwo pressures at the stage concerned exerts an axialthrust opposite in direction to the axial highpressure mentioned above. If the sum of the axial thrusts acting on the individual stages is made equal to the axial high-pressure actr ing on the cross-area of the shaft and corresponding to the end-pressure of the pump, the axial thrusts will balance each other. The shaft 1, then, is relieved and has no need of a special device for taking-up an axial thrust. Inside the tightening-rings 15, 16, due to the borings 19 provided in the wheels, the same pressure prevails on bothsides.

The ball-bearin s 3 and 4 are vso-called radial bearings w ich are movable in an axial direction and will take up the radial strains on the shaft 1. Any further axial thrust, will be taken up by a third bearing 20 which is not movable in an axial direction and is not subject to radial strains. This bearing, thus, fixes the shaft 1 in an axial direction, f. i. by means of the collar 21 and the ring 22, and relieves the two radial bearings 3 and 4 from an axial thrust. The taking-up of the remaining axial thrust ofthe shaft 1 is effected more advantageously by a bearing not movable in an axial direction than vby a so-called axial-bearing, because, with the latter, on account of the centrifugal force acting on the balls a wedging-in of the ballsV will occur in the narrowing space between the grooves of the two bearing-rings.

What -I claimis:

1. A multi-stage high-pressure centrifu gal pump com rising a lurality of impellers on a common s aft, sai shaft being supported only at the suction-side of the pump, the cross-section of the non-su ported end of said shaft being acted upon y an axial highpressure, means provided at a plurality of said impellers for putting in action the pressure generated bysaid imllers on the face of said impellers facing t e suction-side of the pump as a constant axial pressure counteracting the axial high-pressure, whereby a plurality of such pressures counteract othe axialhilgh-pressure and balance it.

2. M ti-stage hi h-pressure centrifugal pump according to c aim 1, wherein the no n-4 supported end of sald shaft enters vthe d1schar chamber of the pump.

3. ulti-stage hi h-pressure centrifugal pump according to c aim 1, said means consisting of tightening-rin ameter being arrange on the face of the im ellers .facing the pump discharge.

witness whereof I have hereunto signed my name.

- ERNST VOGEL.

of diieren't di. ametcrs, the tightenln -ring of greater di` 

